Kyiv, Ukraine — Russia launched dozens of missiles at cities across Ukraine on Monday in an attack that killed at least 31 people and smashed into a children's hospital in Kyiv, officials said. The rare day-time Russian barrage came as President Volodymyr Zelenskyy was due in Warsaw, the Polish government said, before he flies to a NATO summit in Washington.

Explosions rang out and black smoke could be seen rising from the centre of Kyiv, AFP journalists reported.

Pictures distributed by officials from the Okhmatdyt children's hospital in Kyiv showed people digging through mounds of rubble, black smoke billowing over a gutted building and medical staff wearing blood-stained scrubs. Kyiv Mayor Vitaly Klitschko said two people died at the hospital as a result of the strike, including a 30-year-old doctor, and another 16 were wounded, seven of them children.

Klitschko said people's voices were heard from underneath the rubble as rescuers continued digging through the debris. 

"Russian terrorists once again massively attacked Ukraine with missiles. Different cities: Kyiv, Dnipro, Kryvyi Rih, Sloviansk, Kramatorsk," Zelenskyy said, listing major civilians hubs in the south and east of the country.

"More than 40 missiles of various types. Residential buildings, infrastructure and a children's hospital were damaged," Zelenskyy wrote on social media.

The Ukrainian Air Force said the attack included Russian hypersonic Kinzhal missiles, one of the most advanced weapons in the Russian arsenal. Hypersonic missiles can fly at far greater than the speed of sound, making them very difficult to detect and intersect using the missile defense systems available today. Russia has used Kinzhals in previous attacks on Ukraine since it launched its full-scale invasion, but is thought to use the weapons sparingly as they are in limited supply. 

Russian forces have repeatedly targeted the capital with massive barrages since Moscow invaded Ukraine in February 2022, and the last major attack on Kyiv with drones and missiles was last month. In addition to the continuous aerial bombardment of Ukraine's cities and power infrastructure, Russia has also pushed its territorial gains in recent months, making incremental advances along the front line that stretches from Ukraine's northern to southern borders.

The Security Services of Ukraine (SBU) said its initial assessment found that Moscow had struck the Kyiv children's hospital with a KH-101 strategic cruise missile, while Andriy Yermak, senior advisor to Zelenksyy, said the projectile "contains dozens of microelectronics manufactured in NATO countries."  

Russian officials acknowledged the massive missile strike on Monday but denied, as they always do, targeting any civilian infrastructure. The Defense Ministry in Moscow, in statements reported by the country's state-run media, said the strike was a response to attempts by Ukrainian forces "to strike Russian energy and economic facilities," and it claimed it had hit Ukrainian "military industry facilities in Ukraine and aviation bases of the Ukrainian Armed Forces."

The Russian defense ministry said, without offering evidence, that the images of destruction in Kyiv were "due to the fall of a Ukrainian air defense missile."

United Nations humanitarian coordinator for Ukraine Denise Brown harshly condemned Monday's wave of Russian strikes, saying in reference to the hospital that was hit: "It is unconscionable that children are killed and injured in this war."

Ukraine's air force said it had shot down 30 of the 38 missiles launched by Russia in Monday's deadly attack.  

In Zelenskyy's hometown Kryvyi Rih, which has been repeatedly targed by Russian bombardments, the strikes killed at least 10 and wounded over 30, the mayor said.

"In Dnipro, a high-rise building and an enterprise were damaged. A service station was damaged. There are wounded," the Dnipropetrovsk governor Sergiy Lysak added.

In the eastern Donetsk region, where Russian forces have taken a string of villages in recent weeks, the regional governor said three people were killed in Pokrovsk — a town that had a pre-war population of around 60,000 people.

There was no immedate comment on the strikes from the Kremlin but it insists its forces do not target civilian infrastructure.

"This shelling targeted civilians, hit infrastructure, and the whole world should see today the consequences of terror, which can only be responded to by force," the head of the presidential administration in Kyiv, Andriy Yermak, wrote on social media, following the attack.

Zelenskyy and other officials in Kyiv have been urging Ukraine's allies to send more air defence systems, including Patriots, to the war-battered country to help fend off fatal Russian aerial bombardments.

"Russia cannot claim ignorance of where its missiles are flying and must be held fully accountable for all its crimes," Zelensky said in another post on social media.

CBS News' Anhelina Shamlii contributed to this report.

In:
• Hypersonic Missiles
• War
• Ukraine
• Russia
• Vladimir Putin
• Volodymyr Zelenskyy
• Kyiv